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Item
ID MFR code,
device code
Read mode
Standby
Description
Selected by A9 = V
ID
(11.5–12.5V), CE = OE = A1 = A6 = L, enabling outputs.
When A0 is low (V
IL
) the output data = 52h, a unique Mfr. code for Alliance Semiconductor Flash products.
When A0 is high (V
IH
), D
OUT
represents the device code for the AS29F200.
Selected with CE = OE = L, WE = H. Data is valid in t
ACC
time after addresses are stable, t
CE
after CE is low
and t
OE
after OE is low.
Selected with CE = H. Part is powered down, and I
CC
reduced to <2.0 mA for TTL input levels. If activated
during an automated on-chip algorithm, the device completes the operation before entering standby.
Selected with CE = WE = L, OE = H. Accomplish all Flash erasure and programming through the command
register. Contents of command register serve as inputs to the internal state machine. Address latching occurs
on the falling edge of WE or CE, whichever occurs late . Data latching occurs on the rising edge WE or CE,
whichever occurs first. Filters on WE prevent spurious noise events from appearing as write commands.
Hardware protection circuitry implemented with external programming equipment causes the device to
disable program and erase operations for specified sectors.
Disables sector protection for all sectors using external programming equipment. All sectors must be
protected prior to sector unprotection.
Verifies write protection for sector. Sectors are protected from program/erase operations on commercial
programming equipment. Determine if sector protection exists in a system by writing the ID read command
sequence and reading location XXX02h, where address bits A12–16 select the defined sector addresses. A
logical 1 on DQ0 indicates a protected sector; a logical 0 indicates an unprotected sector.
Temporarily disables sector protection for in-system data changes to protected sectors. Apply +12V to RESET
to activate sector unprotect mode. During temporary sector unprotect mode, program protected sectors by
selecting the appropriate sector address. All protected sectors revert to protected state on removal of +12V
from RESET.
Resets the write and erase state machine to read mode. If device is programming or erasing when
RESET = L, data may be corrupted.
Hold RESET low to enter deep power down mode (
<
10 µA CMOS). Recovery time to active mode is 1.5 µs.
Output disable Part remains powered up; but outputs disabled with OE pulled high.
Write
Enable
sector protect
Sector
unprotect
Verify
sector protect
Temporary
sector
unprotect
RESET
)/$6+
Deep
power down
5($'#FRGHV
Mode
MFR code (Alliance Semiconductor)
×8 T boot
Device code
×8 B boot
×16 T boot
×16 B boot
Sector protection
Key: L =Low (<V
IL
); H = High (>V
IH
); X =Don’t care; T = top; B = botto
A16–A12
X
X
X
X
X
Sector address
A6
L
L
L
L
L
L
A1
L
L
L
L
L
H
A0
L
H
H
H
H
L
Code
52h
51h
57h
2251h
2257h
01h protected
00h unprotected
7
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ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
